From 4617721c502b2ddaa4e324e86da4997edf738fa5 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 2 Sep 2026 09:55:01 -0400 Subject: ftrace: Synchronize the initialization of ftrace_ops There's some internal state that ftrace_ops needs to have set, but since it can be declared outside of the ftrace.c code, it calls ftrace_ops_init() on the ops in every global function. The issue is that if two tasks call it on the same ops at the same time it is possible to have the initialization of one corrupt the initialization of the other call. Create a ops_mutex to use to synchronize every initialization of the ftrace_ops. The mutex is taken within checking the ftrace_ops flag that states it was initializied but the flag is checked again after the mutex has been taken. Checking first outside the mutex allows it to shortcut having to take the mutex. But then the check needs to be done again after the mute is taken in case of races. Cc: stable@vger.kernel.org Link: https://patch.msgid.link/20260902095501.6b59af20@gandalf.local.home Fixes: f04f24fb7e48d ("ftrace, kprobes: Fix a deadlock on ftrace_regex_lock") Reported-by: sashiko-bot@kernel.org Close: https://lore.kernel.org/all/20260829025528.49A831F000E9@smtp.kernel.org/ Signed-off-by: Steven Rostedt --- fs/hfsplus/wrapper.c | 240 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 240 insertions(+) create mode 100644 fs/hfsplus/wrapper.c (limited to 'fs/hfsplus/wrapper.c') diff --git a/fs/hfsplus/wrapper.c b/fs/hfsplus/wrapper.c new file mode 100644 index 000000000..30cf4fe78 --- /dev/null +++ b/fs/hfsplus/wrapper.c @@ -0,0 +1,240 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * linux/fs/hfsplus/wrapper.c + * + * Copyright (C) 2001 + * Brad Boyer (flar@allandria.com) + * (C) 2003 Ardis Technologies + * + * Handling of HFS wrappers around HFS+ volumes + */ + +#include +#include +#include +#include + +#include "hfsplus_fs.h" +#include "hfsplus_raw.h" + +struct hfsplus_wd { + u32 ablk_size; + u16 ablk_start; + u16 embed_start; + u16 embed_count; +}; + +/** + * hfsplus_submit_bio - Perform block I/O + * @sb: super block of volume for I/O + * @sector: block to read or write, for blocks of HFSPLUS_SECTOR_SIZE bytes + * @buf: buffer for I/O + * @data: output pointer for location of requested data + * @opf: I/O operation type and flags + * + * The unit of I/O is hfsplus_min_io_size(sb), which may be bigger than + * HFSPLUS_SECTOR_SIZE, and @buf must be sized accordingly. On reads + * @data will return a pointer to the start of the requested sector, + * which may not be the same location as @buf. + * + * If @sector is not aligned to the bdev logical block size it will + * be rounded down. For writes this means that @buf should contain data + * that starts at the rounded-down address. As long as the data was + * read using hfsplus_submit_bio() and the same buffer is used things + * will work correctly. + * + * Returns: %0 on success else -errno code + */ +int hfsplus_submit_bio(struct super_block *sb, sector_t sector, + void *buf, void **data, blk_opf_t opf) +{ + u64 io_size = hfsplus_min_io_size(sb); + loff_t start = (loff_t)sector << HFSPLUS_SECTOR_SHIFT; + int offset = start & (io_size - 1); + + if ((opf & REQ_OP_MASK) != REQ_OP_WRITE && data) + *data = (u8 *)buf + offset; + + /* + * Align sector to hardware sector size and find offset. We assume that + * io_size is a power of two, which _should_ be true. + */ + sector &= ~((io_size >> HFSPLUS_SECTOR_SHIFT) - 1); + return bdev_rw_virt(sb->s_bdev, sector, buf, io_size, opf); +} + +static int hfsplus_read_mdb(void *bufptr, struct hfsplus_wd *wd) +{ + u32 extent; + u16 attrib; + __be16 sig; + + sig = *(__be16 *)(bufptr + HFSP_WRAPOFF_EMBEDSIG); + if (sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIG) && + sig != cpu_to_be16(HFSPLUS_VOLHEAD_SIGX)) + return 0; + + attrib = be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ATTRIB)); + if (!(attrib & HFSP_WRAP_ATTRIB_SLOCK) || + !(attrib & HFSP_WRAP_ATTRIB_SPARED)) + return 0; + + wd->ablk_size = + be32_to_cpu(*(__be32 *)(bufptr + HFSP_WRAPOFF_ABLKSIZE)); + if (wd->ablk_size < HFSPLUS_SECTOR_SIZE) + return 0; + if (wd->ablk_size % HFSPLUS_SECTOR_SIZE) + return 0; + wd->ablk_start = + be16_to_cpu(*(__be16 *)(bufptr + HFSP_WRAPOFF_ABLKSTART)); + + extent = get_unaligned_be32(bufptr + HFSP_WRAPOFF_EMBEDEXT); + wd->embed_start = (extent >> 16) & 0xFFFF; + wd->embed_count = extent & 0xFFFF; + + return 1; +} + +static int hfsplus_get_last_session(struct super_block *sb, + sector_t *start, sector_t *size) +{ + struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk); + + /* default values */ + *start = 0; + *size = bdev_nr_sectors(sb->s_bdev); + + if (HFSPLUS_SB(sb)->session >= 0) { + struct cdrom_tocentry te; + + if (!cdi) + return -EINVAL; + + te.cdte_track = HFSPLUS_SB(sb)->session; + te.cdte_format = CDROM_LBA; + if (cdrom_read_tocentry(cdi, &te) || + (te.cdte_ctrl & CDROM_DATA_TRACK) != 4) { + pr_err("invalid session number or type of track\n"); + return -EINVAL; + } + *start = (sector_t)te.cdte_addr.lba << 2; + } else if (cdi) { + struct cdrom_multisession ms_info; + + ms_info.addr_format = CDROM_LBA; + if (cdrom_multisession(cdi, &ms_info) == 0 && ms_info.xa_flag) + *start = (sector_t)ms_info.addr.lba << 2; + } + + return 0; +} + +/* Find the volume header and fill in some minimum bits in superblock */ +/* Takes in super block, returns true if good data read */ +int hfsplus_read_wrapper(struct super_block *sb) +{ + struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb); + struct hfsplus_wd wd; + sector_t part_start, part_size; + u32 blocksize; + int error = 0; + + error = -EINVAL; + blocksize = sb_min_blocksize(sb, HFSPLUS_SECTOR_SIZE); + if (!blocksize) + goto out; + + sbi->min_io_size = blocksize; + + if (hfsplus_get_last_session(sb, &part_start, &part_size)) + goto out; + + error = -ENOMEM; + sbi->s_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL); + if (!sbi->s_vhdr_buf) + goto out; + sbi->s_backup_vhdr_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL); + if (!sbi->s_backup_vhdr_buf) + goto out_free_vhdr; + +reread: + error = hfsplus_submit_bio(sb, part_start + HFSPLUS_VOLHEAD_SECTOR, + sbi->s_vhdr_buf, (void **)&sbi->s_vhdr, + REQ_OP_READ); + if (error) + goto out_free_backup_vhdr; + + error = -EINVAL; + switch (sbi->s_vhdr->signature) { + case cpu_to_be16(HFSPLUS_VOLHEAD_SIGX): + set_bit(HFSPLUS_SB_HFSX, &sbi->flags); + fallthrough; + case cpu_to_be16(HFSPLUS_VOLHEAD_SIG): + break; + case cpu_to_be16(HFSP_WRAP_MAGIC): + if (!hfsplus_read_mdb(sbi->s_vhdr, &wd)) + goto out_free_backup_vhdr; + wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT; + part_start += (sector_t)wd.ablk_start + + (sector_t)wd.embed_start * wd.ablk_size; + part_size = (sector_t)wd.embed_count * wd.ablk_size; + goto reread; + default: + /* + * Check for a partition block. + * + * (should do this only for cdrom/loop though) + */ + if (hfs_part_find(sb, &part_start, &part_size)) + goto out_free_backup_vhdr; + goto reread; + } + + error = hfsplus_submit_bio(sb, part_start + part_size - 2, + sbi->s_backup_vhdr_buf, + (void **)&sbi->s_backup_vhdr, REQ_OP_READ); + if (error) + goto out_free_backup_vhdr; + + error = -EINVAL; + if (sbi->s_backup_vhdr->signature != sbi->s_vhdr->signature) { + pr_warn("invalid secondary volume header\n"); + goto out_free_backup_vhdr; + } + + blocksize = be32_to_cpu(sbi->s_vhdr->blocksize); + + /* + * Block size must be at least as large as a sector and a multiple of 2. + */ + if (blocksize < HFSPLUS_SECTOR_SIZE || ((blocksize - 1) & blocksize)) + goto out_free_backup_vhdr; + sbi->alloc_blksz = blocksize; + sbi->alloc_blksz_shift = ilog2(blocksize); + blocksize = min_t(u32, sbi->alloc_blksz, PAGE_SIZE); + + /* + * Align block size to block offset. + */ + while (part_start & ((blocksize >> HFSPLUS_SECTOR_SHIFT) - 1)) + blocksize >>= 1; + + if (sb_set_blocksize(sb, blocksize) != blocksize) { + pr_err("unable to set blocksize to %u!\n", blocksize); + goto out_free_backup_vhdr; + } + + sbi->blockoffset = + part_start >> (sb->s_blocksize_bits - HFSPLUS_SECTOR_SHIFT); + sbi->part_start = part_start; + sbi->sect_count = part_size; + sbi->fs_shift = sbi->alloc_blksz_shift - sb->s_blocksize_bits; + return 0; + +out_free_backup_vhdr: + kfree(sbi->s_backup_vhdr_buf); +out_free_vhdr: + kfree(sbi->s_vhdr_buf); +out: + return error; +} -- cgit v1.3.1